1. Field of the Invention
The present invention relates to a static hydraulic continuously variable transmission in which a hydraulic closed circuit is formed between a swashplate type hydraulic pump and a swashplate type hydraulic motor.
2. Description of the Prior Art
Such a static hydraulic continuously variable transmission is known, for example, as described in Japanese Patent Publication No. 38467/84.
In the conventional static hydraulic continuously variable transmission, a pump cylinder of a hydraulic pump is rotatably and slidably disposed to bear against a dispensing board fixedly mounted on a motor cylinder of a hydraulic motor, so that the transferring of a working oil from one to another between the hydraulic pump and the hydraulic motor is conducted through an oil passage penetrating the rotational slide surfaces of the pump cylinder and the dispensing board. Therefore, the hydraulic oil is liable to leak from the space between the respective opposed rotational slide surfaces of the dispensing board and the pump cylinder, resulting in a reduction in transmitting efficiency.